1config HAVE_ARCH_KMEMCHECK
2 bool
3 4if HAVE_ARCH_KMEMCHECK
5 6menuconfig KMEMCHECK
7 bool "kmemcheck: trap use of uninitialized memory"
8 depends on DEBUG_KERNEL
9 depends on !X86_USE_3DNOW
10 depends on SLUB || SLAB
11 depends on !CC_OPTIMIZE_FOR_SIZE
12 depends on !FUNCTION_TRACER
13 select FRAME_POINTER
14 select STACKTRACE
15 default n
16 help
17 This option enables tracing of dynamically allocated kernel memory
18 to see if memory is used before it has been given an initial value.
19 Be aware that this requires half of your memory for bookkeeping and
20 will insert extra code at *every* read and write to tracked memory
21 thus slow down the kernel code (but user code is unaffected).
22 23 The kernel may be started with kmemcheck=0 or kmemcheck=1 to disable
24 or enable kmemcheck at boot-time. If the kernel is started with
25 kmemcheck=0, the large memory and CPU overhead is not incurred.
26 27choice
28 prompt "kmemcheck: default mode at boot"
29 depends on KMEMCHECK
30 default KMEMCHECK_ONESHOT_BY_DEFAULT
31 help
32 This option controls the default behaviour of kmemcheck when the
33 kernel boots and no kmemcheck= parameter is given.
34 35config KMEMCHECK_DISABLED_BY_DEFAULT
36 bool "disabled"
37 depends on KMEMCHECK
38 39config KMEMCHECK_ENABLED_BY_DEFAULT
40 bool "enabled"
41 depends on KMEMCHECK
42 43config KMEMCHECK_ONESHOT_BY_DEFAULT
44 bool "one-shot"
45 depends on KMEMCHECK
46 help
47 In one-shot mode, only the first error detected is reported before
48 kmemcheck is disabled.
49 50endchoice
51 52config KMEMCHECK_QUEUE_SIZE
53 int "kmemcheck: error queue size"
54 depends on KMEMCHECK
55 default 64
56 help
57 Select the maximum number of errors to store in the queue. Since
58 errors can occur virtually anywhere and in any context, we need a
59 temporary storage area which is guarantueed not to generate any
60 other faults. The queue will be emptied as soon as a tasklet may
61 be scheduled. If the queue is full, new error reports will be
62 lost.
63 64config KMEMCHECK_SHADOW_COPY_SHIFT
65 int "kmemcheck: shadow copy size (5 => 32 bytes, 6 => 64 bytes)"
66 depends on KMEMCHECK
67 range 2 8
68 default 5
69 help
70 Select the number of shadow bytes to save along with each entry of
71 the queue. These bytes indicate what parts of an allocation are
72 initialized, uninitialized, etc. and will be displayed when an
73 error is detected to help the debugging of a particular problem.
74 75config KMEMCHECK_PARTIAL_OK
76 bool "kmemcheck: allow partially uninitialized memory"
77 depends on KMEMCHECK
78 default y
79 help
80 This option works around certain GCC optimizations that produce
81 32-bit reads from 16-bit variables where the upper 16 bits are
82 thrown away afterwards. This may of course also hide some real
83 bugs.
84 85config KMEMCHECK_BITOPS_OK
86 bool "kmemcheck: allow bit-field manipulation"
87 depends on KMEMCHECK
88 default n
89 help
90 This option silences warnings that would be generated for bit-field
91 accesses where not all the bits are initialized at the same time.
92 This may also hide some real bugs.
93 94endif
95